The American Geophysical Union's warning reflects an increasingly vocal scientific community.
Stepping up the pressure for political action on global warming, scientists for the second time in two months have called for strong measures to curb greenhouse-gas emissions.
The American Geophysical Union (AGU) – the world's largest scientific organization dedicated to Earth, atmospheric, and space sciences – warned Thursday that the world will need to reduce emissions by 50 percent below 1990 levels within this century if countries are serious about holding down warming to around 3.6 degrees F. by 2100.
Significantly warmer temperatures over that period would lead to seriously disruptive changes for societies as well as for ecosystems around the planet, many scientists say.
The statement is the strongest the AGU has made since it first took a stance on the issue in 1998.
The warning comes on the heels of a similar call at the United Nation's global climate talks last month in Nusa Dua, Indonesia. There, scientists released the "Bali Declaration," which calls on negotiators to craft a new climate treaty that will aim to cut greenhouse-gas emissions by at least 50 percent below 1990 levels by 2050 to avoid what UN treaties refer to as "dangerous" human interference with climate.
Although the three major reports released last year by the UN's Intergovernmental Panel on Climate (IPCC) usually provide the scientific framework for policy debates on global warming, the AGU's statement is also likely to be influential, especially for those who distrust the UN, some analysts say.